SABRA AND SHATILA

Published: December 28, 1986

To THE Editor:

John P. Roche, reproving what he calls ''egregious exaggeration'' of the Phalangist massacre at the Sabra and Shatila refugee camps in Lebanon in 1982, writes that the ''official report of the Lebanese Government,'' stating that just 425 men were killed, and 35 women and children, ''has not been seriously challenged'' (Letters, Dec. 7).

This is nonsense. First, there was no Lebanese investigation in any real sense of the word and no final report was ever issued to the public in any detail, so no wonder it was never ''seriously challenged.'' The bogus casualty figures Mr. Roche cites were leaked by Lebanese officials, who were interested in playing down the number of women and children killed, from what they said was the ''official report.''

Second, the Lebanese so-called investigator was Assad Germanos, a Maronite Christian, who was at the time the chief military prosecutor. He told me, as correspondent for The New York Times in Lebanon, that his investigative team, which included only seven people, was trying to solve 3,572 other outstanding cases while investigating the massacre. I asked Mr. Germanos, four months after his supposed investigation had begun, whether he had interviewed Elie Hobeika, the Phalangist militia commander named by Israel as the mastermind of the killings; he told me, ''I've heard of him, but I have not actually spoken to him.''

Finally, the only organization that kept even partial records of the dead was the International Committee of the Red Cross, which helped to bury many of them in a mass grave. The committee, according to its report, which is available in its Beirut office, listed 356 people as having been buried - 146 by friends and relatives and 210 by the Red Cross. Of the 210 the Red Cross buried, 38 were women, 32 were children and 140 were men of all ages. The same one-to-three proportion of women and children to men is assumed to apply to the other 146 known buried and the other several hundred buried by family and never recorded - a far cry from Mr. Roche's figures.

No doubt many young Palestinians of fighting age were killed. I saw bodies of all ages. But I have news for Mr. Roche: if there had been as many ''terrorists'' in the camp as he claims, they would have been strong enough to defend themselves and there never would have been a massacre. THOMAS L. FRIEDMAN